Improvement in steam-boilers



P. SALISBURY & 11. 0. SMITH.

Steam-Boiler.

No. 207,133. Patented Aug. 20,1878.

Whaiwem: ak/3221020.

Q W M convenient mechanism.

UNITED STATES PATENT OFFIon "eEone r. SALISBURY AND HENRY e. srnrmor newHaven. ooxn'.

IMPROVEMENT IN STEAM-30d LERS.

- Specification forming part of Letters PatentfNol 207,133, dated August20,1378; application filed April 5,1878.

To all whom it may concern: 7

Be it knownthat we, GEonGE l. SALIS- BURY and HENRY (3. SMITH, of NewHaven,

in the county of New- Haven and State of Connecticut, have inventedcertain new and.

useful Improvements in Steam-Boilers; and

we do hereby declare that the following is a This invention mares 'tos'team boilers; and

consists in the construction, combination, and

arrangement of the devices hereinafter described.

In the accompanying drawings, Figure 1 represents a verticallongitudinal section of a steam-boiler embodying our invention, takenthrough the line a: w of Fig. 2. Fig. 2*represcnts a plan view of thesame, taken partly in section, on the line 3 y of Fig. I; and Fig. 3represents a transverse vertical section through the line a z of Fig. 2.r V

A designates thecylindrical body of the I boiler; B, the fire-tubes,extending longitudinally through the same; C,the plates to which theends of said tubes are attached; I), the smoke-box; E, the smoke-stack;F,- the front water-leg, and N the rear water-leg.

To provide the requisite strong draft we employ an exhaust-fan, Z, whichis inclosed in a chamber or curved independent passage, 2,

which opens at one end into the said smokestack, and at the other endinto the said smokebox. -It is inclosed in a protectingcasing, whichprevents all communication with the outer air. This fan may be operatedby any 1 It acts'wholly as an exhaust, drawing the air through thefurnace and fire-tubes, and deliveriu git to the smokestack.

Damper X regulates the draft by closing the base of smoke-stack E moreor less, as desired. When; said stack is closed at the bottom by saiddamper the draft is strongest; but in proportion to the size of theopening close connections at both ends.

will be the downward pressure of the air tending. to neutralize thedraft.

W designates a vertical diaphragm in the back part of the furnace, andseparated from its rear wall by a space, c. said diaphragm supports theinner ends of grate-bars G, which may be tubular in form.

. The fire-box is completed by a horizontal partition or top'plate, V,which extends from the inner face of the frontof the furnace to the topof'said vertical diaphragm, forming zontal partition protects thecrownplate from being injured by sudden changes of temperature when coldair-rushes inon opening the.

door. y

The chief use of. diaphragm W is'to allow a downward draft to be used,thus avoiding waste of light particles of fuel and efi'ecting otherdesirable results. To start the fire an upward draft is,however,.desirable. -This is eflected by opening dampers t t in thebottom of the furnace and damper w in the upper part of diaphragm W.When these dampers are closed the draft is downward.

T designates a series of water-tubes extending across the furnace,slightly inclined, and arranged so as to be wholly embedded in the fuel.They extend from water-leg F to waterleg N, and serve for the generationof steam, and to produce acirculation of water therein. Their inclinedarrangement facilitates the escape of steam, and by embedding them inthe fuel we insure the application of a greater degree of heat than theycould receive if merely subjected to the blaze below the fuel. N

H designates two or more perforated airpipes extending across thefurnace horizontally below the grate, and supplying air for com bustion.

The outer air for the draft enters the furnace I through draft-door a.

Having thus described our invention, what we claim as new, anddesire tosecure by Let ters Patent, is

1. The combination of a smoke-stack, smoke= 'box, and device forregulating thedraft with an exhaust-fan operating connection with theindependent passage leading from the The lower edge of Thishorismoke-box to the smoke-stack, to produce a In testimonythat we claimthe foregoing as draft through the furnace-fines, smoke box, our own weafiix our signatures in presence of and up the stack, as shown and setforth. two witnesses. t

2. The exhaust-fan Z, operating in connee GEORGE P. SALISBURY. tion withthe independent passage leading HENRY 0. SMITH. from'the smoke-box tothe smoke-stack, to pro- Witnesses:

duce a draft through" the furnace-fines, smoke- GEORGE TERRY, box, andup the stack, as shown and set forth. ROGER M. SHERMAN.

